Message Query

The following message appeared in a popup window. What does it mean You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?' at line 9

SELECT *, SUM(correct) as correct, SUM(incorrect) as incorrect, (SUM(correct)*6+SUM(incorrect)) AS score, (SUM(correct)+SUM(incorrect)) AS total FROM `scores` WHERE pid = ?